With the development of electronic technologies, various kinds of electronic apparatuses have been developed and distributed. In particular, televisions (TVs) are able to provide 3D contents or contents of higher resolution, and accordingly, development of technologies for providing a content including a plurality of images like a 3D content, a multi-angle content, and a content having depth images or a content of ultra high definition (UHD) level image quality is ongoing.
A channel bandwidth used in an existing broadcasting network is limited, whereas a multi-angle content, a 3D content, or a content of UHD level image quality has a data size greater than that of the existing content. Therefore, the existing broadcasting network has difficulty in transmitting the content of the great data size as it is.
Investing in new equipments to provide new contents may incur much cost. Existing broadcasting equipments and receiving apparatuses should be used to provide new contents. Accordingly, a method of transmitting reference multimedia data from among a plurality of multimedia data included in a multimedia content through an existing broadcasting network and transmitting additional multimedia data through a transmission path which his different from the existing broadcasting network may be considered.
However, when data is transmitted through different transmission networks, respective multimedia data use independent encoders. System clocks of the respective encoders do not match each other and thus it is difficult to add the same synchronization information.